1. Field of the Invention
The present invention relates to an amusement ride vehicle for travel along a trackway defined by a pair of track rails, and more particularly to a vehicle incorporating drive wheels and pinch wheels which cooperate for increased driving traction and protection against vehicle separation from the track rails.
2. Description of Related Art
In a typical amusement ride, a train of vehicles is propelled along a pair of spaced apart track rails that define a trackway which changes in elevation and follows an irregular or serpentine path. A tractor or propulsion vehicle connected to a string of passenger vehicles form the ride train. More than one propulsion vehicle may be needed depending upon the weight of the loaded train and the grade to be negotiated.
One known form of propulsion vehicle incorporates motor driven driving axles having drive wheels which run on top of the track rails. Up-stop or vehicle separation protection is provided by fixed members which project beneath and engage the rails when there is any excessive upward travel of the vehicles. This function is sometimes served by up-stop.
Since the number of passenger vehicles that can be pulled or safely braked by a propulsion vehicle is a function of the train weight and the grade of the trackway, a significant number of additional propulsion vehicles are required for long trains or for steep grades.
Various systems have been advanced in the prior art for increasing the traction between a propulsion vehicle and a trackway so that greater loads can be carried including, by way of example, the systems of U.S. Pat. No. 3,648,617, issued Mar. 14, 1972 to Metzner al., and 3,584,583, issued June 15, 1971 to Cartwright. These systems are not specifically addressed to amusement ride vehicles in which it is important to have not only optimum traction but also constant up-stop protection and in which it is further important to accomplish this by mechanisms which will not interfere with periodic separation of the vehicle from the tracks for maintenance, storage or the like.